Gene Tunney, the boxing champion?s son who was elected Sonoma County?s district attorney in 1974 and became renowned as a crime victim?s advocate, died Sunday.

Tunney, who was a mentor to people throughout the county?s criminal justice system during his 20 years as chief prosecutor, died at his Tiburon home from complications of the cancer he?d fought since shortly after his retirement in 1994. He was 77.

He and his wife of 49 years, Ann, recently moved to Marin County after living for a decade on the island of Hawaii, where they swam in the ocean every day.

Tunney?s integrity, commitment to justice and lust for life were cited most often by both former colleagues and courtroom adversaries. With his love of flying, adventure, story-telling and books, there was a Jack London quality to the man.

?He was a champion for the victims of crime long before it was popular,? said Tunney?s successor, former District Attorney J. Michael Mullins.

Current Sonoma County District Attorney Stephan Passalacqua, whom Tunney hired as a deputy prosecutor in 1989, called him ?well read, well traveled and well respected.?

Criminal defene attorney Chris Andrian observed that Tunney came from a boxing family ?and was a bit of a bulldog himself.?

?But I always described him as a bulldog with a heart of gold,? said Andrian, who regarded Tunney as a mentor. ?He was stern, he was certainly no pushover, but he had a sense of justice about him.?

Many of Tunney?s deputy prosecutors went on to become judges. One, Sonoma County Superior Court Judge Mark Tansil, said he remembers most that Tunney never allowed politics to dictate how his office would prosecute a case or whether it would accept a plea bargain.

?It was always what was right, based on the facts and law,? Tansil said. The judge and former prosecutor added, ?I was really proud to work for him. He had a great mind and an exceptional sense of humor.?

People close to Tunney also said he was foremost a family man.

?Although he devoted his career to public service, he always put his family first,? said daughter Alexandra Kelly of San Diego. ?Everyone who knew him thought he led primarily by his example of how to live a just and productive life.?

Tunney was born in New York on Nov. 18, 1931, and was fitted with a big name. Three years earlier, his father, James Joseph ?Gene? Tunney, had retired as America?s heavyweight boxing champion and one of the biggest names in the sport.

Educated at Yale University, the boxer?s son could have pursued wealth and fame in any number of fields ? early on he tried international banking ? but he found his passion in criminal law.

He?d married and started a family when he enrolled at the University of San Francisco to complete a quest for a law degree that had been interrupted by a tour of duty in the Army.

In 1968, Tunney became a deputy prosecutor in Alameda County. He left the job two years later to join the U.S. Senate campaign of his younger brother, John Tunney, a congressman from Southern California who would go on to serve six years in the Senate.

Gene Tunney?s first job in Sonoma County was defending people accused of crime. Former Public Defender Marteen Miller hired him as a deputy in mid-1971.

Two years later, Tunney declared he would run against Sonoma County District Attorney John Hawkes. Tunney won. Shortly after taking office in 1974 he declared that no plea bargains would happen without his approval and that he would personally review all felony cases.

He recalled in a 1993 interview with The Press Democrat that when he became DA, the deputy prosecutors were ?all doing their own thing? and making plea deals he would not have allowed.

There were critics who complained that as county prosecutor Tunney was autocratic and too controlling of his deputies. Admirers credit him with raising the standards of the District Attorney?s Office and building it from a rural-county operation to one that rose to the challenge of dealing with increasingly urban crime.

?He made a professional organization of it, one that had very high standards,? said former District Attorney Mullins, now a prosecutor in Solano County.

Tunney perceived a need to bring greater professionalism and more uniform charging standards to county prosecutors? offices across the state. Another of his objectives was to make the job of prosecuting attorney more desirable as a career.

Former Solano County District Attorney and semi-retired judge Mike NailNail was an early president of the California District Attorney?s Association, which Tunney co-founded. He said Tunney?s leadership improved the way DA?s offices work and enhanced their ability to attract career prosecutors.

Noting that many of Tunney?s deputy DA?s went on to the bench, former Sonoma County supervisor Jim Harberson said, ?He obviously trained them well.?

Nick Esposti, another ex-supervisor who worked with Tunney, appreciated that he was direct and no-nonsense. ?He never blind-sided you,? Esposti said.

Away from work, Tunney loved to fly small planes with his wife, a fellow pilot, and to swim, read and travel.

When his four kids were young, ?He loved to drag us to historical sights around the country,? said daughter Kelly. ?Wherever we traveled, he would find the nearest point of historical interest.

?He had a near-photographic memory and a desire to read and constantly learn throughout his whole life ? and to share that knowledge with all of us,? she said. ?Dinner conversations were lengthy, lengthy.?

In addition to his wife in Tiburon and his daughter in San Diego, Tunney is survived by daughters Megan Muldoon Tunney of San Diego and Erin MacLeon of Cedar Park, Tex.; son Gene Varick Tunney of Tiburon; brothers John Tunney of Sun Valley, Idaho, and Jay Tunney of New York City, and seven grandchildren.

A vigil service will be held at 4 p.m. today<NO1>Friday<NO> at St. Hilary Catholic Church in Tiburon. A Funeral Mass will be celebrated at the church at 11 a.m. Saturday.